Manufacturers of food products and beverages for human consumption typically package the beverage or food product. A variety of substances may be used to provide packaging for the products, including, but not limited to, plastics and glass. As a specific example, soft drinks typically are packaged in bottles formed from polyethylene terephthalate, otherwise known as "PET bottles." However, other plastics are also well known to the beverage and food packaging industries for use as containers for food and beverage products.
Current practice in the industry, and in particular for the packaging of soft drinks, is to rinse PET bottles with municipal water prior to filling the bottle with a soft drink. The use of hot water or chemical disinfectants typically has not been considered suitable for rinsing PET bottles prior to filling because hot water or disinfectants could chemically or physically alter the characteristics of a PET bottle. Such alterations could render the bottles unsuitable for containing beverages, or adversely affect the quality or taste of the beverage, or render the beverage unsuitable for human consumption.
Various devices and processes have been proposed for sanitizing containers such as bottles by contact with an ozonated rinse water. Ozone is highly reactive and is an effective oxidizing agent for sanitizing containers. Ozonated rinse water has the advantage over untreated rinse water of effectively removing microbes and other contaminants without changing the chemical or physical nature of the container. For example, Silberzahn U.S. Pat. No. 4,409,188 proposes a device for sterilizing containers that comprises a rotatable immersion wheel for immersing the containers in a bath of ozone and water. Numerous other devices using ozone as a sanitizing agent have also been proposed.
Hughes U.S. Pat. No. 5,106,495 proposes a portable water purification device that uses ozone as a treatment agent. Water in a tank is circulated by a pump through a venturi where ozone is injected into the water, which is then returned to the tank.
Burris U.S. Pat. No. 5,082,558 proposes a contact lens purification system in which sensors detect the concentration of ozone in the treatment liquid, and a controller acts responsibly to the sensor to control the residence time of the lenses in the system in response to the concentration of ozone.
McConnell et al. U.S. Pat. No. 4,795,497 proposes a method and a system for the fluid treatment of semiconductor wafers in a sequence of fluids and uses a closed fluid recirculation loop and a means for holding the wafers in the fluid flow path. In one embodiment, ozone is bubbled through the treatment fluid to enhance cleaning.
In spite of these previous devices and methods for using ozone as a sterilizing or cleaning agent, the food and beverage industry, and in particular the soft drink industry, still relies on municipal water supplies for rinsing PET containers prior to filling with soft drink. The rinse water typically is not recirculated, resulting in the run off of thousands of gallons of waste water and the high costs of operation associated with such a great use of municipal water supplies.
It would be desirable to develop an apparatus and process for sanitizing articles for food grade products, and in particular for plastic containers such as PET bottles for soft drinks, that could provide an automated recirculating operation of a captive and ozonated water supply. Such an apparatus and method could be effective to remove microbiological contaminants from food grade containers prior to filling with beverages or other food products without adversely affecting either the physical or chemical nature of the container. Additionally, by using a captive water supply, such an apparatus and process could save thousands of gallons of water, resulting in a substantial savings of money.